Rachey the Christmas Eve Hamper is a lovely thing to do - and ignore any nay-sayers who do the " Whhhaaaaat another present? They don't need something on the 24th"
The CEH isn't about presents. It's the preparation and the Winding Down (vital with over excited DC on Christmas Eve)
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We used to take them for a walk (park or ducks) just as it was getting dark. I'd do the Wait I need to check the back door is locked and put the boxes by the fire for them to 'find'
Lush BathBombs are good too. They do unglittery ones if you don't want your bath to look like Liberace has invaded but don't put them with an foodie things, they stink it out.
We did a jar of sweets each too.
Small pack of biscuits and a sachet of hot chocolate
(No DVD in ours though, that's on Netflix)
The PJs - Primark do nice festive ones only £5ish
The biscuit mix sounds gorgeous - maybe have a couple of trial runs? You could try gingerbread men - layer up the flour/sugar/ginger to make it stripey in the jar and melt the butter and syrup. Then you have all the fun of rolling it out.
Or easier would be a cookie mix (rub in the flour/butter on the day then layer with sugar, chocolate chips. Tip it out add an egg and roll into a sausage to chill and slice)
I did Reindeer foos ONCE . Porridge oats, sugar and pink food colour and edible glitter (don't use craft glitter) Lakeland sells it.
It sat like a lump of ..you can guess by my description...untouched by the birds till I scooped it up.
I save jars (just random jam jars) put candles in and line them u the path to light the way for The Sleigh.
One year I made an Elf ( an old soft bath toy with a muslin cloth face, hat made of felt. drew a sleeping face) I put it in a tiny box bed in the Playhouse, DS and I walked down with a candle light to peep at him.
"He's very tired so Santa asked if he could sleep here. Santa will collect him when he brings your presents" (Of course he has to be gone before DS remembers him 
Look on eBay for Large Old Keys you can get some spectacular ones to paint gold , just a couple of £. Tie with a ribbon.
And if she's old enough - put wrapping paper (cheap big rolls ) across the door for her to burst through.
Quite sad in a way that I have pesky teens who don't indulge me !